A sewing machine including a needle bar having a sewing needle, a spindle for driving the needle bar, a bed portion movable selectively to a using position or a retracted position, and a rotary hook housed in the bed portion. A stitch is formed by the cooperation of the sewing needle and the rotary hook. A rotary hook drive motor is provided in the bed portion for driving the rotary hook. A sensor is provided for detecting a position of the bed portion. The needle bar and the spindle is selectively disconnected from each other. If the bed portion is out of the using position, and this out position is detected by the sensor, the needle bar is released from the spindle for stopping the sewing needle. Further, in this case, the rotation of the rotary hook drive motor is also stopped.